Title: DMA on XINTF write not working on TMS320f28335, whereas on read it works well. DMA on XINTF write not working on TMS320f28335.

Title: DMA on XINTF write not working on TMS320f28335, whereas on read it works well.

Configuration:
a. 28335 XINTF zone 0 is interfaced with COM20022i Arcnet controller. XINTF zone 0 of 8 words have been mapped which is
DMA accessible.
b. The Address lines and data lines has been connected.
c. There is only one ISR mapped for both receive (XINTF read) and transmission (XINTF write)
d. Two different DMA channels has been used for XINTF read and XINTF write. DMA channel 3 for read and 4 for write
e. The XINTF timing for both read and write is same where in lead, active and trail has been configured as follows:
   i. Lead = 3
   ii. Active = 7
   iii. Trail = 3
DMA configuration:
a. Src and destination burst step is 0
.
b. Scr wrap step is 1 and Destination is 0. Wrap count is set to maximum value
c. DMA peripheral select is 0, One shot is enabled, 16 bit transfer is enabled, Interrupt is enabled towards end of DMA
transfer
d. DMA transfer step size for source is 1 and destination is 0 (as destination is only data register)

Issue Description:
a. The 28335 writes/reads into the Data register of the COM20022i Arcnet controler whenever it needs to transmit/receive data
b. The DMA works well for read for any number of words but does not work for write. The very first time it sends the
packet properly but later all the words are zero. It appears that COM20022i controller itself is not getting the words
properly.
c. However the DMA works if we write word by word, but this not useful as we are able to write the words using XINTF
data gets written always properly.
d. Since we have requirement of writing more words we wanted to use DMA and that is not working.

Note:
a. We cannot read back the data written to controller nor we can veryify the words on Oscilloscope.
b. The same configuration of DMA works well if buffer mapping is done on XINTF zone 0 and written to that buffer

We are unable to proceed further on this issue as what could be wrong as DMA configuration is correct and word by word
works well.